Sustainable emulsifiers from plant-based protein hydrolysates: A comprehensive review of food industry applications

Plant-based protein hydrolysates (PBPHs) have garnered significant attention as natural emulsifiers in the food industry owing to their biocompatibility, sustainability, and potential to substitute synthetic surfactants. This review provides a comprehensive overview of the mechanisms, applications, and future directions of protein hydrolysates (PHs) as emulsifiers in food systems. The emulsifying properties of PHs are influenced by several factors, such as degree of hydrolysis, type of protein and enzyme used, pH, ionic strength, peptide molecular weight, solubility, particle size, and temperature. Several bioinformatics tools, including ExPASy Peptide Cutter, PSIPRED, COILS, Computed atlas of surface topography of proteins (CASTp), and Emulsipred, are currently used to predict emulsifying peptides based on their amphiphilic characteristics, interfacial properties and secondary structures. PBPHs derived from peanut, sunflower, sesame, soybean, rapeseed, rice bran, wheat bran, corn gluten meal, chickpea skin, potato peels, grape seed residues, and tomato pomace have been utilised as an emulsifier in various food applications, such as bioactive compound encapsulation, meat products, dairy products, mayonnaise, and packaging films. Emulsions stabilised by PHs exhibit improved physical and oxidative stability and enhanced shelf life. This review underscores the potential of PHs as a natural plant-based emulsifier in the food industry.